1. Technical Field
The present invention relates to a spectroscopic measurement device and a spectroscopic measurement method.
2. Related Art
In the past, there has been known a variable wavelength interference filter having a pair of reflecting films opposed to each other and varying the distance between the reflecting films to thereby take out the light having a predetermined wavelength out of the light as the measurement object. Further, there has been known a spectroscopic measurement device for measuring the optical spectrum of the light as the measurement object using such a variable wavelength interference filter as described above (see, e.g., JP-A-7-243963 (Document 1)).
The optical resonator (the variable wavelength interference filter) described in Document 1 is provided with a first substrate having a surface provided with a recessed section, and a second substrate, wherein the second substrate is bonded so as to block up the inside of the recessed section of the first substrate. Further, the bottom portion of the recessed section of the first substrate and the surface of the second substrate opposed to the recessed section are respectively provided with high-reflecting films opposed to each other and electrodes for regulating the gap (inter-reflecting film gap) between these reflecting films. Further, the second substrate has a thick-wall portion and a thin-wall portion disposed in a region opposed to the recessed section, and it becomes possible for the thick-wall portion to move back and forth toward the recessed section due to the deflection of the thin-wall portion.
In such a variable wavelength interference filter, it becomes possible to regulate the inter-reflection film gap by making the thick-wall portion move back and forth toward the first substrate by deforming the thin-wall portion as a diaphragm by applying a voltage between the electrodes.
Incidentally, in the case of taking out the light with the target wavelength using such a variable wavelength interference filter as described above, the voltage corresponding to the target wavelength is applied between the electrodes. On this occasion, since the electrostatic attractive force due to the application of the voltage and the elastic force of the thin-wall portion of the second substrate act on the thick-wall portion of the second substrate, the thick-wall portion vibrates.
Therefore, in the past, in order to accurately measure the light with the target wavelength, such a spectroscopic measurement device using the variable wavelength interference filter waits until the vibration of the thick-wall portion settles, and then performs the light intensity measurement process after the vibration of the thick-wall portion has settled. Therefore, there is a problem that the time required for the measurement increases.
In particular, in the spectroscopic measurement device, it is necessary to sequentially change the wavelength as the measurement object in a predetermined wavelength band, and measure the light intensity of each wavelength. Therefore, if such a stand-by time as described above is provided to every measurement object, there is a problem that the time required for the measurement further increases.